Strand traverse mechanism



Dec. 15, 1953 H. w. BALLARD STRAND TRAVERSE MECHANISM Filed Dec. 19, 1952 INVENTOR. HYDE W BA LLA RD way/2 ATTORN Patented Dec. 15, 1953 UNITED STATES PATENT ()FFICE STRAND TRAVERSE MECHANISM Application December 19, 1952, Serial No. 327,007

11 Claims. 1

This invention relates to traverse or builder mechanism for winding threads or strands into packages. The device is designed primarily for high speed winding of thread or yarn onto a mandrel such as a bobbin, tube, core, or the like.

As discussed in Nydegger Patent 2,238,128 and Heizer Patent 2,611,548, the problems incident to satisfactory high speed winding of yarn packages are more critical than when the package is wound at comparatively slow speeds as formerly practiced. Briefly, the inherent objections to previous forms of traversing mechanism may be summed up as follows: (1) Any mechanism which uses direct simple harmonic motion is unsatisfactory because a level package is not produced due to the dwell at each end; (2) Likewise any oscillating structure produces some build-up at the ends of the package even though direct simple harmonic motion is not used, because the oscillatguide or member must be decelerated to zero and accelerated to normal traversing speed at the end of each stroke; (3) In devices of the type employing rotating cam surfaces for contacting the yarn, it has been found impossible to limit the yarn contact to a single surface with a single straight shaft for the cams. This, in turn, causes the yarn to follow a zigzag path, and the friction incident to such additional yarn contact at high speed is undesirable.

Both the Nydegger and Heizer devices referred to above are examples of attempts to overcome one or more of the above disadvantages. However, the present invention represents a further advance in several important respects. It is simple, inexpensive to construct and does not require saecial gearing or shaping of the yarn guiding surface. Also, it provides accurate control of the yarn both during traverse and at the ends of the stroke. This is effected Without undue friction on the yarn strand or likelihood of entanglement in the guiding structure.

A primary object of the invention, therefore, is to provide a simple, inexpensive yarn traversing mechanism suitable for high speed operation.

A further object of the invention is to provide a yarn traversing mechanism characterized by upper and lower flexible belts traveling in opposite directions and having the innermost span of each belt set at an angle to a yarn control slot or guide.

A further object of the invention is to provide improved means for controlling the point of yarn disengagement with a pair of oppositely traveling yarn guiding belts.

Further objects will be apparent from specification and drawings in which;

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Figure 1 is a front view of an improved yarn traverse mechanism constructed in accordance with the present invention;

Figure 2 is an end view of the apparatus of Figure 1;

Figure 3 is an enlarged fragmentary detail partly sectioned, showing the left hand end of the yarn guide and its associated structure; and

Figure 4 is an enlarged fragmentary detail showing the right hand end of the yarn guide and its associated structure.

The invention comprises essentially the provision of a lower, endless belt having one or more pegs or lugs on the outer periphery of the belt which are positioned to engage a length of yarn and move the yarn in one direction as it is being wound upon a bobbin. A complementary upper belt likewise has a peg or lug on its periphery which engages the yarn strand to move it in the opposite direction after it has become disengaged from the peg on the lower belt. The lower span of the upper belt and the upper span of the lower belt are substantially parallel to each other, and are set at an angle to the centerline of an elongated yarn guide so that when the yarn reaches one end of the guide, it is automatically pulled off of the peg on the particular belt with which it was engaged. Simultaneously, the peg on the opposite belt picks up the yarn at the base of the peg and carries it to the opposite end of the guide at which time the yarn slips off the peg due to the angularity between the yarn guide and the belt span. Desirably, the yarn controlling belt spans are accurately positioned at the point of yarn disengagement by means of intermediate pulleys.

Referring now more particularly to the drawings, a preferred embodiment of the present invention comprises a belt [0 which is mounted on pulleys H and I2 both turning in a counterclockwise direction. A lower belt l3 is similarly mounted on pulleys M and it which turn in the same counterclockwise direction as pulleys l l and I2. Each of the belts It and I3 is provided with a one or more pegs or abutments ES, ll, !8 and 19 which extend outwardly from the backs of the belts. It will be understood that suitable driving connections (not shown) are provided for the four pulleys, it being important only that the pulleys for the upper and lower belts turn in timed relation to each other so that the relative positions of the pegs iii-49 are accurately controlled. To assist in maintaining the proper timing between the belts, they may, if desired, be provided with teeth 20, 29 around their inner edges which mesh with teeth 2!, 2| between the flanges of the pulleys (Figure 3).

A strand of yarn or other filamentary material S is shown being wound onto a bobbin or tube T which is mounted and turned in a winding machine in manner well known in the art. The continuous winding of the strand S onto the tube T forms a package P of yarn which should be nearly cylindrical in shape. In order to accomplish this result, I slant the upper span l3a of belt [3 and the lower span Illa of belt it) with respect to the centerline of tube '1 and package P. As shown in Figure 2. the belts l0 and I3 are offset slightly in a vertical plane with respect to each other so that the pegs on the respective belts do not interfere. It will be understood that it is desirable to position the belts as near a common vertical line as possible provided sufliciont clearance for the pegs is maintained.

A yarn guide Eiiwhich in the pre ent embodiment comprises a len th of wire formin an elongated aperture s positioned or mounted directly in back of upper belt iii and as clo e thereto as possible without interfering with the operation of the belt. The purpose of yarn guide 25 is to provide closely controlled path for the yarn in its back and forth travel. Desirably, the height of the aperture or slot formed by the guide is just sufficient to permit free travel of the yarn being wound thus reducing to a m nimum the permissible vertical movement of the yarn. The guide may be formed as shown in Figure 1 or it may consist of a slot in a part of the winding machine. In the preferred embodiment as illustrated in Figures 1 and 2, the guide 25 is self-threading, in that it is not necessary to insert an end of the strand through the guide. The operator can hook the strand over the bent-up end 25a of the guide to position the strand correctly therein.

In operation, the strand is attached to the tube T in the conventional manner after having been threaded through the guide 25 or inserted therein as described above. With the machine thus laced up, one of the pegs in sweeping across in front of the yarn gu de picks up the strand and carries it towards one end or the other of the guide. At this point, which is predetermined in accordance with the length of the package desired, the strand automatically disengages from the peg and is simultaneously picked up and carried back across the guide by a peg on the oppositely fac ng belt. Figure 3 shows the relative position of the yarn strand and the pegs just as the strand is.

about to become disengaged from peg It on belt :3. carefully calculated in conjunction with the slant of the spans ita and Ida so that when the strand S reaches the predetermined end or" the package, it slips off the end of the peg l6. Simultaneously, the peg ll on belt iii traveling in the oppos te direction picks up the strand which contacts the peg near its base and the strand is carried across the guide 25 by peg ll until it nears the opposite end of the guide. Due to the length of peg H and the angularity between the span liia and the guide 25, the strand slips over the end of the peg ii at a predetermined point in its traverse. Figure l shows the positition of the strand just after it has slipped out of control of peg I! and just as it is picked up by peg [9 on belt 13. g

In order to insure that the strand slips over the end of the peg at the proper point in its traverse, a pair of positioning guide pulleys 3B and 31 may be provided in alignment with the end of the package or the point where the strand slips over For this purpose, the length of the pegs is the pegs. To prevent any whip which might otherwise occur in the spans Illa and I 3a from interfering with the proper disengagement of the strand from the pegs, the spans its and l3a diverge at pulleys 3t and 3i thus insuring positive positioning of the pegs at this point in their travel. Naturally, it will be understood that the angularity of the belt spans with respect to the guide 2.",- may be varied as desired and in turn the length or the pegs would be so calculated that the strand slips oil the pegs at the desired point. Accurate control of the strand at the point of disengagement is also provided by the proximity and. height of the, yarn guide 25 together with the precise positioning of the spans by means of pulleys 3i! and El. However, unless there is a tendency for the strand S to whip up and down, it may, under certain conditions, be possible to eliminate the guide 25 entirely. In this respect, the provision or added tension on the strand will be or" importance. For this purpose, the strand guiding eyelet may be replaced with any well known strand tensioning mechanism,

As shown, the spans and 3c are substantially parallel to each other. This condition, however, is not absolutely essential but it enables all the pegs to be of substantially the same length.

The leading faces of the pegs should be formed with a suflicient radius to inhibit any injury or damage to the strand and the angle or other contour of the faces of the pegs will be formed in accordance with the type of yarn being wound and the speed with which the belts are operated.

I have thus provided a simple and inexpensive yet positively controlled yarn traversing mechanisrn for winding bobbins or coils of filamentary material. The belts employed may be of the usual rubber or synthetic rubber impregnated fabric thus insuring smooth, quiet, high speed operation. The pegs secured in the belts can have a vitreous coating to minimize friction between the pegs and the yarn. There is ample ability adjust the mechanism for all types of material, package sizes and winding spec s.

Having thus described my invention, I claim:

1. A traversing mechanism comprising a pair of belts mounted in juxtaposed position with respect to each other, a strand guiding span on one of said belts, an oppositely-facing and oppositely traveling strand guiding span on the other of said belts, said spans being biased with respect to the traversed path of the strand, strand engaging means of each of said belts, the length of said strand engaging means being such that thestrand passes over the end of said engaging means at a pre-selected point in the strand traverse path.

2. Apparatus as defined in claim 1 in which the belts are of flexible non-metallic material.

3. Apparatus in accordance with claim 1 in which the belts and the pulleys are provided with intermeshing teeth.

4. Apparatus in accordance with claim 1 having an intermediate belt control pulley in alignment with the point of strand disengagement with the strand engaging means on the belt.

5, Apparatus in accordance with claim 1 in which the spans are substantially parallel to each other.

6. Apparatus in accordance with claim 1 having means for retaining the strand in a substanmeans for driving said belt, a second flexible belt, means for driving said second belt in timed relation with the first belt, a yarn guide positioned in closed spaced relation to adjacent spans of said belts, the centerline of the yarn guide be-- ing biased with respect to the spans of the belts, means on each of said belts for engaging a yarn strand passing through the guide and traversing the strand back and forth in the guide in accordance with the belt traverse, and means for rigidly fixing the position of each belt span at a point adjacent the termini of the strand guide.

8. In yarn winding and traversing mechanism, the combination which comprises a mandrel on which a yarn package is formed, a yarn traverse guide forming an elongated slot having a height slightly greater than the diameter of a strand to be wound, the centerline of said guide being parallel to the centerline of the mandrel, a pair of endless flexible non-metallic belts mounted in juxtaposed position with respect to each other adjacent said guiding means, a substantially straight span on one of said belts positioned in close spaced relation to, and biased with respect to the centerline of the guiding means, a substantially straight oppositely-facing span on the other of said belts positioned in close spaced relation to the first span and biased in the same direction as said first span, means for driving said belts in the same direction so that the spans travel in opposite directions, and at least one strand engaging element on the outside of each of the belts for traversing the strand bacl: and forth across the guiding means.

9. Apparatus in accordance with claim 8 in which the belts and the pulleys are provided With intermeshing teeth.

10. Apparatus in accordance with claim 8 having an intermediate belt control pulley in alignment with the point of strand disengagement with the strand engaging means on the belt.

11. Apparatus in accordance with claim 8 in which the spans are substantially parallel to each other.

HYDE W. BALLARD.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,238,128 Nydegger Apr. 15, 1941 FOREIGN PATENTS Number Country Date 972,440 France Aug. 30, 1950 

